I was wondering if anyone could help me with this. I have a carvin tube amp and I just bought a footswitch for it (channel select). It works fine, but when I switch to the clean channel it makes a loud popping sound (audible through speakers). I'm hoping it's not something serious. This is the only tube amp I have ever owned so I am not sure as to what could be the source of the problem. Repair shops can be expensive and I don't live in an area where there are a lot of them to choose from. If there is anyone out there that could shed some light on this for me, it would be greatly appreciated.